24 May 2006

US Energy Initiatives Corporation, manufacturer of a dual-fuel diesel to natural gas conversion systems, recently has completed development of a system for a Series 60 Detroit diesel used in a waste collection application, and has activated a Daewoo WD6L engine at the Natural Gas Vehicle Institute (NGVI) facility.

The US Energy dual-fuel system supports the replacement of up to 80% of the diesel with natural gas, and can produce reductions in NOx emissions by at least 23%, according to the company.

Korea has 5 million diesel vehicles—3 million of which are cargo vehicles—out of 15 million total vehicle population. The country is the second largest importer of LNG in the world after Japan. The Korean fuel price of diesel is US$ 1.20/liter while that of CNG is only US$ 0.54/liter. Korea has allocated US$5 billion to be applied over the next ten years through the Seoul Metro Clean Air Project for after-market conversions and after-treatment of diesel vehicles.

The Daewoo system was put on a developmental fast-track at the request of our client, US-based NGVI. We completed our field installations with our chief programmer in Korea ensuring the system was running smoothly. NGVI has notified us that they intend to follow-up the successful Daewoo conversion with a Hyndai 13 liter and a Daewoo 15 liter.

—US Energy CEO Mark Clancy

The Series 60 System is applied to a 2005 Sterling truck used by the Solid Waste Authority of Central Ohio (SWACO). The engine is fitted in a truck/tractor and is used in bulk trash transferring in the Columbus, Ohio Region.

Fuel for the truck will be generated from landfill gas at facilities managed by SWACO. The first truck will be evaluated for 3-6 months and a decision will be made regarding converting 25 additional trucks.

US Energy is also involved in two other lines of business: a biofuels division with a mandate to develop a biodiesel which, when used in conjunction with the CNG conversion systems, results in further reduction of diesel emissions below regulatory levels; and a related technology incubation division which will be charged with locating and licensing and/or acquiring promising young energy technologies.

The company also just acquired Encore, an energy management company that advises Fortune 500 companies and procures energy (natural gas, diesel, gasoline) for its clientele at the best possible rates.

Liquefying natural gas requires a lot of energy and the product is somewhat dangerous to transport. According to wikipedia, the required temperature is -120 to -170 deg C (103-153 deg K). Specific volume is just 1/600 of the gaseous phase.

The exergy of the cold ought to be put to good use. Cryogenic gas motors force the liquid fuel to boil off at high pressure, which is then used to drive a turbine. The fuel is not combusted. Considering the cryotechnology and mass flows required, the only sensible application would be for electricity generation at the LNG receiving terminal.

However, afaik, the most common current practice is to let the LNG boil off by heating it with seawater, wasting he cold exegy. There are also negative consequences for marine life near the harbor due to the reduced water temperature:

Wrt using natural gas as a vehicle fuel in countries that rely on LNG supplies rather than pipelines, there is a good case for chemical liquefaction (GTL using Fischer-Tropsch synthesis) near the gas field. GTL is still quite expensive. However, it's a much better fuel than regular diesel. The maximum blend fraction possible without vehicle modifications depends on the diesel fuel specification in the target market. In Europe it's about 37%, constrained by required minimum density.

Methane is a renewable energy source, from gasification process of inedible biomass. This would be a lot quicker, cheaper and more efficient than cellulosic ethanol. Add a little bit of hydrogen to the methane and make the combustion process a lot more efficient, and a lot cleaner than burning diesel fuel. So, it's a wise move to convert diesel to natural gas. In Pakistan, 1 million vehicles already use natural gas.